FREQUENCY OF CELLS EXPRESSING CD44, A HEAD AND NECK CANCER STEM CELL MARKER: CORRELATION WITH TUMOR AGGRESSIVENESS

Background. We previously identified by flow cytometry a Lineage-CD44+ (Lin-CD44+) subpopulation of cells with cancer stem cell properties in head and neck squamous cell carcinoma (HNSCC). We now correlate clinical and histologic factors with Lin-CD44+ cell frequency. Methods. The study included 31 patients with HNSCC, of whom 87% had stage IV disease. The frequency of Lin-CD44+ cells and the success of xenografting patient tumors in mice were correlated with clinical and pathologic data. Results. The mean frequency of Lin-CD44+ cells was 25% (0.4%-81%). It was 36% in patients who had recurrence versus 15% for those without recurrence (p = .04). Successful xenograft implantation occurred in 53%. Seventy-five percent of patients with successful xenografts had recurrence versus 21% of patients with unsuccessful xenografts (p = .003). Conclusions. Successful xenograft implantation and a high frequency of Lin-CD44+ cells correlate with known poor prognostic factors such as advanced T classification and recurrence. These findings may support the stem cell concept in HNSCC. (C) 2011 Wiley Periodicals, Inc. Head Neck 34: 42-49, 2012